Importance of shallow water habitats for demersal fishes and decapod crustaceans in Penobscot Bay, Maine

We characterized demersal fish and decapod crustacean habitats in 14 shallow (< 12 m) areas in Penobscot Bay, Maine, by mapping the distribution of subtidal substrata with an acoustic sea bottom profiler. We identified the aquatic vegetation and the fishes and decapods associated with these habitats. Samples of fishes and decapods in each habitat were collected with a small beam trawl. The seabed at most of the stations sampled was composed of a mosaic of substrata. More species of fishes tow(-1) and higher abundances of fishes and decapods were found in stations with vegetation present, particularly eelgrass, Zostera marina. Decapod species richness tow(-1) was similar between vegetated and unvegetated habitats. Shallow habitats in Penobscot Bay were dominated by juvenile fishes and function as nursery areas. The greater species diversity and higher abundances of epibenthic fishes and decapod crustaceans observed in vegetated habitats, particularly beds of Zostera marina, compared with unvegetated areas in Penobscot Bay conform to the hypothesis that increased habitat complexity results in increased species richness and abundance.